General Martin Dempsey, US Chairman of the Joint Chiefs of Staff, told reporters Wednesday during his China visit that Beijing was "working on" North Korea.
China is the North's only major ally and its most significant trading partner, and Beijing has in the past been reluctant to throw its weight around when it comes to North Korea.
But Pyongyang's bellicose rhetoric, its recent nuclear bomb test that resulted in harsh new UN sanctions, and escalating military tensions have all likely tried China's patience with Kim Jong Un.
"I will leave here with the belief that the Chinese leadership is as concerned as we are with North Korea's march toward nuclearization and ballistic missile technology, and they have given us an assurance that they are working on it, as we are," Dempsey told reporters.
Dempsey added his analysis of the Korean crisis, saying North Korea is “in a period of prolonged provocation rather than cyclical provocation.” He said “the risk of miscalculation is higher" and "the risk of escalation is higher."
Dempsey ends today his visit to China, where he met with high-ranking military officials and Chinese President Xi Jinping. His visit is the latest in a series talks between the US and China over North Korea's nuclear program.
US Secretary of State John Kerry visited South Korea, Japan and China earlier in April, and stressed China's importance in negotiations with North Korea.
"I think it is very important to the Chinese to focus on the fact that ... if they're not prepared to put the pressure on the North - and they have the greatest ability to have an impact on the North - then this can become more destabilizing,” Kerry said.
The US is not the only country seeking China's help.
South Korean Foreign Minister Yun Byung-se traveled to China on Wednesday to talk with his Chinese counterpart Wang Yi in Beijing.
"I expect to make efforts with Minister Wang, who has an extensive knowledge on issues with regard to the Korean Peninsula and Northeast Asia, to open a new chapter for the development of Korea-China relations," Yun said in his opening remarks.
Still, for all the work towards a diplomatic solution, the US and its allies have not reduced their military presence or capability.
"Our military posture is one of deterrence and preparedness," Dempsey said. "And if they were to launch, we do have the capability to defend ourselves, our people, our facilities, and we've been very clear about that."